Fertility testing and ICSI sperm selection by hyaluronic acid binding: clinical and genetic aspects

The testis-expressed chaperone protein, HspA2 (previously creatine kinase M isoform) was established as a measure of human sperm cellular maturity, function and fertility. The presence of HspA2 in the synaptonemal complex is likely to link low HspA2 expression and increased frequency of chromosomal aneuploidies in arrested-maturity spermatozoa. A relationship also exists between HspA2 expression in elongating spermatids and the associated spermatogenetic events, including plasma membrane remodelling and the formation of zona pellucida and hyaluronic acid (HA) binding sites. The HA receptor of mature spermatozoa, when coupled with HA-coated slides and/or Petri dishes, allows visual observation of sperm-HA binding, providing a basis for sperm maturity testing, a major improvement in semen evaluation, and selection of mature spermatozoa for intracytoplasmic sperm injection (ICSI). Thus, in HA-selected spermatozoa the frequency of chromosomal disomy and diploidy is reduced 4- to 6-fold compared with semen sperm fractions. This reduction is similar to the increase in numerical chromosomal aberrations in ICSI children. Combined studies of sperm shape and chromosome probes demonstrated that sperm morphology does not aid selection of haploid spermatozoa. The HA-mediated sperm selection is a novel and efficient technique that may alleviate potential problems related to ICSI fertilization with visually selected spermatozoa.

Immunohistochemical detection of CD45+, CD56+, and CD14+ cells in human decidua during early pregnancy

The densities and distribution of innate immune system cells, NK cells and macrophages, was investigated between days 22-30 post coitus of very early pregnancy. Paraffin sections were labelled by the avidin-biotin complex-peroxidase method using monoclonal antibodies specific for CD45, CD56 and CD14. Positive cells were quantified and the results were analysed using ANOVA tests. It was found that ~40% of all cells were leukocytes and ~30% of the leukocytes were NK cells and ~22% were macrophages. The number of CD56+ cells increased as pregnancy progressed. CD56+ were observed cells close to the luminal epithelium and were especially noticeable around glands where they often occurred in small clusters. Decidual macrophages (CD14+) were distributed throughout the decidual stroma of early pregnancy and were observed in greatest numbers around the vessel walls. Their numbers have also increased as pregnancy progressed. The great abundance of these leukocytes, which are known as members of the innate immune system, in early pregnancy decidua suggests that these cells are important for fetal survival and pregnancy success. The relevance of the distribution of CD45+, CD56+ and CD14+ in decidua at the fourth week of pregnancy to the immunological barrier between mother and fetus is discussed.